Toolholder for multiple punch presses



Jan. l19, 1965 w. BREDow TOOLHOLDER FOR MULTIPLE PUNCH PRESSES 2 Sheets-Sheet l Filed NOV. 1'?. 1961 [iwi Jan. 19, 1965 w. BREDow 3,165,962

TOOLHOLDER FOR MULTIPLE PUNCH PRESSES Filed Nov. 17. 1961 2 Srheets-Sheet '2 F/g. 2 f

/E Z 74K TOOLHOLDER FR MULTIPLE PUNCH PRESSES Walter Bredow, Vormasch 2, Alfeld (Leine), Germany Filed Nov. 17, 1961, Ser. No. 153,1tl1 Claims priority, appiieaton Gzermany, Mar. 7, 1961,

i 4 claims. (ci. S31- 540) This invention relates to a toolholder for multiple punch presses. Multiple punch presses of Various types are already known to the art. A feature which is common to all these multi-punch presses is the provision of a major number of tools in a rotatable tool head to permit diiferent holes to be punched, for instance, into sheet metal blanks without the need of exchanging the tools. Generally, such multiple punch presses'are also equipped with a compound slide table which permits punching to proceed without previously marking out the work. In other types of multiple punch presses 'the tools are held` in a segment-shaped head which is rotatable about a vertical axis. However, the tools may be held ina head of some other shape, provided means are provided for for indexing the head.

In known multiple punch presses the rotatable die and punch plates -containing the tools or a corresponding toolholder are mounted in the machine frame.v This machine frame must be constructed to withstand the reactive punching thrusts, and if the cross sections used in the construction of the frame are to be within economical limits, the frame is subjectedy to elastic deformation which frequently exceeds permissible limits. This elastic deformation affects the angular position of the arms of the frame and hence causes the punches to be'deected out of the theoretical perpendicular in which the strokeof the `punch should take place. This displacement of the y type frame comprising a tool head for one or more tools in the gap of the frarneis provided with'a special bear-V ing frame located without constraint in the gap of the C-shaped main frame in such manner that any deformation of the main frame cannot alect the bearing frame. In other words the proposed arrangement is such that deformation of the main frame cannot generate stresses in the bearing frame. The bearing frame is therefore secured in the gap of the main frame when viewed from the side at any suitable point, i.e. at `a point which cannot transmit deformations of the main frame to the supplementary bearing frame. However, it is primarily intended to apply the invention to multiple punch or indexing tool head presses. According to the invention the C- shaped bearing plate is provided in the gap of the main frame and secured preferably by -bolting its lower limbv to the lower part of the main frame. The lower and upper limbs of the bearing frame contain the pivot pins for punch and die plates. Naturally,V segment-shaped plates may take theplace of completely circular punch and die plates.

The accompanying drawings illustrate an embodiment of the invention in the case of a punch press with a rotatable tool head.- In the drawings FIGURE l is aside elevation ofthe press showing only those parts which are relevant to the invention, and

f ice FIGURE 2'is ai section of the'machinetaken on the4 lineI-II in FIGURE 1.

Located in the C-shaped frame 1 -ofmthe machine isi a likewise C-shaped bearingframe 2 which is gapped on` the same side as `the main frame and therefore has the shape of an overturned U when viewed from the. side.

VOnly the bottomV limb of 'this bearing Aframeiislbolted ati." 3 to the outer wallsn of the main frame 1 abo-ve theytable.

The bearing frame carries the pins 4 andr5 about which the two parallel rotatable tool plates 6 and 7,A can index.

The punching pressures or 'rather' the reactive thrusts tem may be replaced by an eccentric or the thrust may be relation to the dies in the lower plate.

are transmitted by ram 8 throughthe toggle lever system` 9 to pin 10 with such toggle lever system Abeing driven by push rod 18 and are thus taken up by the outer main frame` 1 of the machine. Naturallyna toggle lever sysgenerated by a hydraulically operable ramcylinder.' The bearing frame 2 does not` therefore participate in taking up the thrust and it is not subject to detectable deforma. i tion so'that the Vpunches retain their correctpositions in.

The thrust generated when stripping the perforated blank, vwhich may be equal to about 10% of the thrust requiredfor punching,

is transmitted by the lstripper plate 11, thepunch platef 7 andV the backing jpin 12 directly to the mainframe -1 of the press. The described arrangement thus solves the problem of providing a support for the punch, or toolholder which isl not affected by the action of the reactive forces on the machine frame 1 engendered during the punchingiand stripping operations.

The drawings show the tools 14 in the upper @the tools having a hemispherical head.15 which engages bearing frame located' in the gap of the main frame, thel a recess 16 in ram 8 for the central transmission of thrust. The machine frame 1 is mounted on a pedestal 17, beingsecured thereto by screws 19. p l

In the illustrated embodiment of a punch press with a rotatable Vtool head the main frame 1 consists of two upright side plates of considerable height located in two parallel planes. This arrangement permits the bearing frame 2 to be interposed between the two spaced plates of the main frame 1 and to besecured exclusively by bolts 3 which connect the lower limbof the bearing frame 2 with the bottom part of the main frame. Themain frame includes a slideway Zllbetween the two side plates thereof and the ram is slidably disposed in such slideway.

Alternatively the bearing frame might be located'rin a recess of the main frame in such manner that any de? formation of the main frame 1 cannot laffect the bearing fratrie. l

I claim:v

1. In a punch press, a C-shaped Vmain frame, a rotatable die plate mounted in the gap ofthe frame, a

bearing frame being unstressed by deformation of the main frame, a rotatable punch plate supported by the.

bearing frame in the gap of the'mainframe, a plurality of punches slidablyV disposed in the Vpunch plate, and a ram slidably disposed in the main frame and .engageable with any selected lone of the punches to operate the latter so that `only forces in an axial direction are transmittedrby the ram and punch with all forces generatedY during v operation of a punch being absorbed directly by the main frame and the bearing frame being unstressed by such forces. f ,1

2. In a punch press, a C-shaped main lframe, a bearing frame located without restraint in the gap of the main frame, a rotatable die plate supported by the bearing frame, a rotatable punch plate supported above the die plate by the bearing frame, a plurality of punches vvslidably disposed in the punch plate, `and a ramslidably disposed in the main frame and engageable with any selected one of the punches to operate thelatter sothat only forces Patented Jan. 1,9., 1965' plate, j

in an axial direction yare transmitted by the ram and punch Withall reactive forces generated during operation of a punch being transmitted by the ram to the main frame and the bearing frame being unstressed by such forces and `beingrunstressedby deformation of the main frame.v

`3. In a punch press, ya C-shaped main frame, a C- shaped bearingrfrarne located in the `gap of the main frame,

the bearing -frame having a lower limb fastened to the lower limb of the mainframe and being otherwise unrestrained, a rotatable die plate supported in the said gap by the lower limb of the bearing frame, a rotatable punch plate supported `in the gapand above the dieplate by the upper limb of the bearing frame, aplurality of punches s lidably disposedY in :the punch plate, and a ram slidably disposed in the main frame and engageable with any `selected punch`to operate the latte-r so that only forces in an'axial direction are transmitted by the ram and punch with all forces generated during operation of a punch being transmitted to the main frame and the bearing frame being Vunstressed by such forces.

4. In a punch pressr two spaced Vparallel ,C-shaped side plates constituting a main frame,A a pivot pin disposed between 'the upper limbs of the side plates, a -shaped bearing frame disposed between the sideplates, the bearing frame having its lower limb bolted to the lower limbs of the side ,A plates and being otherwise unrestrained, a

rotatable vdie plate supported within the gap of the mainv frame bythe lower limb f the bearing frame, a rotatable Vpunch plate supported within the gap by .the upper limb of the bearing frame, a backing pin bearing between the upper limb of the main frame and the top of the punch plate, a plurality of punches slidably disposed in the punch plate, a rarn slidably disposed in the said main frame and engageable with a selected punch to operate the latter, a toggle lever system coupling the ram to the said pivot pin, and means for flexing the toggle lever system to actuate the ,raml so that only forces in an axial direction are transmitted by the ram and punch with all reactive forces generated during operation of -a punch being transmitted by way of the ram, backing pin, toggle lever system and pivot pin to the main frame. v

References Cited by the Examiner ANDREW RJUHASZ, Primary Examiner.

CARL W. TOMLlN, HUNTER KVC. BOURNE, JR.,

LEON PEAR,-Examners. 

1. IN A PUNCH PRESS, A C-SHAPED MAIN FRAME, A ROTATABLE DIE PLATE MOUNTED IN THE GAP OF THE FRAME, A BEARING FRAME LOCATED IN THE GAP OF THE MAIN FRAME, THE BEARING FRAME BEING UNSTRESSED BY DEFORMATIONS OF THE MAIN FRAME, A ROTATABLE PUNCH PLATE SUPPORTED BY THE BEARING FRAME IN THE GAP OF THE FRAME, A PLURALITY OF PINCHES SLIDABLY DISPOSED IN THE PUNCH PLATE, AND A RAM SLIDABLY DISPOSED IN THE MAIN FRAME AND ENGAGEABLE WITH ANY SELECTED ONE OF THE PUNCHES TO OPERATE THE LATTER 